Key Points:

Weapons used by the three services of the New Zealand military, the army, the navy and the air force, are to be upgraded at a cost of millions of dollars.

The New Zealand Defence Force has begun a study of 10 weapons systems, mostly small arms issued to soldiers, sailors and airmen.

However, although the 13,000 Steyr rifles which have been in service for 20 years, would not be replaced, they would be a significant part of the upgrade programme.

The study would look at modifying about 3000 of the 13,000 5.56mm rifles so they could take more fittings on the top rail, instead of the factory-fitted 1.5 magnification sighting system

However, the light support system, the 5.56mm Minimi light machine gun would be replaced. It was first issued in 1988 and was expected to come to the end of its useful economic life in about 18 months.

The study would also include the 9mm Sig Sauer pistols, first introduced in 1992, shotguns, sniper rifles and the Carl Gustov anti-tank weapon first introduced in 1989.

NZDF spokesman, Lieutenant Colonel Hugh McAslan, said the Steyr rifles would be upgraded rather than replaced because they were in good condition and there were few other comparable options on the market.

Steyr ammunition would also be in the trial to see if a more powerful round would improve the versatility of the rifle.

"We have got a whole range of questions we need to answer through the testing and evaluation activity."

Lt Col McAslan said the Steyr rifles could be used in Afghanistan where they could be shooting at an enemy 400 metres away or in the jungles of East Timor where they could be only 10 metres away.

He said the demands on weapons from different environments would be included in the evaluation.

He said the NZDF wanted another 10 years of life out of the Steyrs but the 3000 to be upgraded would be able to be fitted with a range of sights and ancillary options such as white light and aiming systems.

The Steyr upgrade would begin next year and finish in 2011 but the entire programme would be completed in 2014 and would cost about $33 million.